A TRIAL with 13 otherwise normal cars running on biodiesel is due to start next month as part of Singapore's first testbed project involving the fuel.

The two-year project was initiated in December and the first diesel-engined car - one of 13 Volkswagen and Mercedes-Benz diesel models - arrived some time towards the end of the first quarter of this year.

After various tests, they began running on conventional diesel fuel last month, with the ultra-low sulphur diesel (ULSD) supplied by Shell. This first phase of the project is to establish a reference point for the study.

When the cars have clocked 2,000 km each - expected to be some time in the middle of next month - the second phase will start with the use of 'B5 biodiesel', which is a blend of 5 per cent palm oil methyl esters (Pome) and 95 per cent ULSD.

The 13 cars are being used by the project partners and they bear blue-and-yellow 'RD', or research & development, licence plates, which are meant for government-sanctioned trial projects.

The cars include a few VW Touareg SUV and Touran MPV models, as well as a couple of VW Passat sedans.

There are also a handful of diesel-engined Mercedes-Benz S-Class limousines and an ML320 CDI sport-utility vehicle.

The project was originally supposed to have involved two more cars but it is understood that two Mercedes-Benz saloons did not come with the required diesel particulate filters. Even without the filters, all of the diesel cars comply with the stringent Euro 4 emission standard. But the project's aim was to evaluate the emission and fuel consumption of the cars fitted with particle filters.

The project co-ordinator is Bosch, a leading maker of diesel-engine systems. The others in the nine-member group are DaimlerChrysler, which is providing the Mercs, Volkswagen Group Singapore, the Economic Development Board, the National Environment Agency, Kuok Oils and Grains, Shell, Nexsol and Diesel Tech.

The two carmakers were chosen because they are leaders in the field of diesel technology and offer a wide range of diesel models.

The project, the aim of which is to establish greater understanding of the use of palm oil methyl esters as a motor fuel in climate conditions like those prevailing in South-east Asian countries, began with December's memorandum of understanding signed by the group.

Palm oil was chosen over other commonly used biological sources like sugar cane or corn because it is cheaper and in plentiful supply. Malaysia is the world's top producer of palm oil, and Indonesia is a close second.

During the project, each of the various members will get the use of one or more of the cars. The vehicles also undergo various consumption and performance measurements.

The biodiesel is being produced at a US$20 million refinery on Jurong Island. This esterification plant will also satisfy Europe's growing demand for biofuels.

The European Union requires biofuels to make up 5 per cent of its member countries' transportation fuels.

In the Singapore trial, the particular proportion of Pome to ultra-low sulphur diesel was chosen because it is said to be the optimum combination without excessive viscosity.

After the biodiesel tests are completed, the results will be announced to the public at a ceremony in early December.

The project is expected to result in economic benefits because of the biofuel's export possibilities, as well as position Singapore as a leader in the new technology.